# Estimating Sums and Differences Worksheets

How to Estimate Sums - Math is, for sure, a very tricky subject, but there are many questions and many definitions within the subject that are easy and fun to solve. If you have problems regarding what estimation is and you are unsure of how you can estimate a sum, then follow some very simple steps, and you will learn it in no time! But before we start, do you know what estimation is? Let us take a quick review! Estimation is a rough idea of what the value is equal to without having a proper idea of the number. Estimation requires operating mentally, and often there is no need to get an exact result, instead only an idea or an estimate is required of the outcome. Here is what you need to do to estimate a problem: 1. We only round the summands to the nearest tenth. 2. So, you need to remember that if the number is less than 5, we round down. 3. And if the number is 5 or greater than 5, we round up estimate. 4. Now, add the rounded numbers! 5. You are done!

• ### Basic Lesson

Demonstrates quick rounding strategies. Also includes practice problems. Estimate the sum or difference of each problem.

• ### Intermediate Lesson

Uses a larger number sets than the basic lesson.

• ### Independent Practice 1

20 problems ask you to estimate the sums and differences. The answers can be found below.

• ### Independent Practice 2

20 practice problems that review rounding techniques. The answers can be found below.

• ### Homework Worksheet

12 problems to reinforce the lessons and practice pages. An example is provided.

• ### Skill Quiz

10 problems that test large sums and differences estimation skills.

• ### Homework and Quiz Answer Key

Answers for the homework and quiz.

• ### Lesson and Practice Answer Key

Answers for both lessons and both practice sheets.

• ### Basic Lesson

Students learn pre-algebra skills to prepare them for higher level operations. Also includes practice problems. Create an addition or subtraction problem based on the given answer. 1. Put a number in place of the circle. 2. Put a number in place of the rectangle that makes the equation true.

• ### Intermediate Lesson

Uses larger number set for sums and differences than are presented in the basic lesson. Create an addition or subtraction problem based on the given answer. Replace the circle. Replace the rectangle to make the equations true.

• ### Independent Practice 1

20 practice problems with a solution and operators present. The answers can be found below.

• ### Independent Practice 2

20 more problems for you. Answer keys can be found below.

• ### Homework Worksheet

Contains 12 problems. Two examples are provided.

• ### Making Sums and Differences Quiz

10 problems that test introductory algebra skills

• ### Basic Lesson

Demonstrates how to estimate sums and differences by comparing pictures. Also includes practice problems. Estimate the sum or differences of each problem by comparing pictures.

• ### Intermediate Lesson

Uses a larger picture sets than the basic lesson.

• ### Independent Practice 1

10 problems ask you to estimate the sums and differences of groups animals. The answers can be found below.

• ### Independent Practice 2

10 problems ask you to estimate the sums and differences of groups animals and dinosaurs. The answers can be found below.

• ### Homework Worksheet

8 problems to reinforce the lessons and practice pages. An example is provided.

• ### Skill Quiz

10 problems that test visual sums and differences estimation skills.

• ### Homework and Quiz Answer Key

Answers for the homework and quiz.

• ### Lesson and Practice Answer Key

Answers for both lessons and both practice sheets.

### How to Estimate Large Sums and Differences

Estimating differences is just like estimating sums. Difference is when you subtract one number from the other. The steps of estimation are almost the same. For example, if it’s a two-digit number then our aim to estimate to the nearest 10 meaning that there are two numbers. If it is a three-digit number, then you need to round it about or make an estimation to the nearest 100.

The second step is to subtract the new numbers. But remember you are not getting the exact answer. Estimation can only bring you as close as possible to the actual answer but be the accurate figure. This process is often carried out when money is involved. For example, having enough money in the supermarket to get the groceries. For example, when you have \$40 and you want to buy groceries that are going to cost you around \$28. So, you round it about to the nearest tenth which is \$30.

58 estimated 60 (Nearest tenth). 33 estimated 30 (Nearest tenth). 60 – 30 = 30. This 30 is your estimated answer and difference and not the actual answer.

#### Practice Time

Here is some fun practice for estimating:
estimate the check at a restaurant or the cost of your groceries in the cart.
If you have a picture of a large number of items, portion off a section and count how many items are in that section. You can then multiply by how many sections there are in the whole picture.
This is sometimes called "clump counting."